The Crystal Structure of Elpidite
nova and Belov are the doubling of the cell parameter 6, the centric space group, and the improved accuracy of the atomic parameters. The refined structure, using Weissenberg data, yielded a final R index of 0.07. fntroduction The crystal structure of elpidite NazZrSioOrs.3H2O was solved by Neronova...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.515.764 http://rruff.info/doclib/am/vol58/AM58_106.pdf |
| Summary: | nova and Belov are the doubling of the cell parameter 6, the centric space group, and the improved accuracy of the atomic parameters. The refined structure, using Weissenberg data, yielded a final R index of 0.07. fntroduction The crystal structure of elpidite NazZrSioOrs.3H2O was solved by Neronova and Belov (1963) and described in the centrosymmetric space group pmcm.l In a later paper, the same authors (1964) lowered the symmetry to P2cm in order to explain certain features of the electron density map. The least squares refinement carried out on the basis of this latter space group led to a final discrepancy factor ot O.2l.It was impossible for the Russian authors to obtain a more satisfactory R factor and accurate values of interatomic distances using the imperfect, twinned crystals from Lovozero, Kola peninsula, U.S.S.R. Elpidite was recently found in silicate veins and vugs of the nepheline syenite of Mt. St. Hilaire(Quebec, Canada) and described by Chao (1967), who reported the following lattice parameters: a = 7.14, b: 14.68, c = 14.58 A; the D cell parameter is twice the value of Russian elpidite. The availabil-ity of perfect single crystals of elpidite from Mt. St. Hilaire suggested a revision of the crystal structure of this mineral. |
|---|